The present application relates to a nonaqueous electrolyte battery. In more detail, the present application relates to a nonaqueous electrolyte battery using a nonaqueous electrolyte containing an organic solvent and an electrolyte salt.
In recent years, portable electronic appliances such as a camera-integrated VTR (video tape recorder), a mobile phone and a laptop PC (personal computer) have widely spread, and it is strongly demanded to realize downsizing, weight reduction and long life thereof. Following this, the development of batteries as a power source of portable electronic appliances, in particular, secondary batteries such as lithium ion secondary batteries which are lightweight and which are able to obtain a high energy density is advanced.
In the field of such a lithium ion secondary battery, the research for enhancing battery characteristics such as cycle characteristics and a battery capacity is energetically conducted, and various technologies for enhancing the battery characteristics and battery capacity have been proposed.
For example, JP-A-10-275632 discloses a technology for enhancing safety by allowing an electrolytic solution to contain an alkyl group-containing nonionic aromatic hydrocarbon compound.
JP-A-2001-167791 and JP-A-2002-298909 disclose technologies for enhancing battery characteristics by allowing an electrolytic solution to contain a tert-butylbenzene derivative.
JP-A-2006-309965 discloses a technology for enhancing battery characteristics by allowing an electrolytic solution to contain tert-pentylbenzene and 4-fluoro-1,3-dioxolan-2-one.
JP-A-2008-186792 discloses that lithium carbonate to be contained in a positive electrode is decomposed at the beginning of overcharge to generate a gas, and a pressure-sensitive safety mechanism is actuated in an early stage, thereby enhancing safety. Also, JP-A-2008-186792 discloses that a cycloalkylbenzene compound and/or a compound having quaternary carbon adjacent to a benzene ring acts so as to suppress a lowering of high temperature cycle characteristics by the addition of lithium carbonate, whereby the high temperature cycle characteristics are tremendously enhanced.
Also, in order to contrive to attain a higher capacity of a lithium ion secondary battery, it is proposed to use, as a positive electrode active material, lithium nickelate (LiNiO2) or a nickel based lithium complex oxide obtained by substituting a part of nickel of lithium nickelate with other metal.